Vacuum type circuit breaker comprising series-connected vacuum interrupters, individual ones of which are readily removable and replaceable

ABSTRACT

A vacuum-type circuit breaker comprises a plurality of vacuum circuit interrupters stacked one above the other and electrically connected in series. For mounting the interrupters, a pair of horizontally-spaced, vertically-extending channels of insulating material are provided. Extending horizontally between the webs of the channels are a plurality of interrupter-supporting plates, to which the interrupters are respectively secured. Each of these plates is detachably connected to the webs and, when detached, is removable laterally of the channels from the space between the webs to permit the plate together with its associated interrupter to be removed from the circuit breaker.

United States Patent [191 Sharp REMOVABLE AND REPLACEABLE William '1.Sharp, Philadelphia, Pa.

General Electric Company, Philadelphia, Pa.

Filed: Mar. 7, 1972 Appl. No.3 232,568

Inventor:

[73] Assignee:

US. Cl. 317/103, 317/112, 200/144 B Int. Cl. H02b 1/04 Field of Search200/144 B, 145;

References Cited UNITED STATES PATENTS 3,397,293 8/1968 Darrow 200/144 BX 3,594,525 7/1971. Miller 200/144 B FOREIGN PATENTS OR APPLICATIONS1,080,198 8/1967 Great Britain 200/144 B [451 Dec. 18,1973

Primary Examiner-Robert K. Schaefer Assistant E.raminer--Gerald P. TolinAttorney-J. Wesley Haubner et al [57] ABSTRACT A vacuum-type circuitbreaker comprises a plurality of vacuum circuit interrupters stacked oneabove the other and electrically connected in series. For mounting theinterrupters, a pair of horizontally-spaced, vertically-extendingchannels of insulating material are provided. Extending horizontallybetween the webs of the channels are a plurality ofinterrupter-supporting plates, to which the interrupters arerespectively secured. Each of these plates is detachably connected tothe webs and, when detached, is removable laterally of the channels fromthe space between the webs to permit the plate together with itsassociated interrupter to be removed from the circuit breaker.

4 Claims, 4 Drawing Figures VACUUM TYPE CIRCUIT BREAKER COMPRISINGSERIES-CONNECTED VACUUM INTERRUPTERS, INDIVIDUAL ONES OF WHICH AREREADILY REMOVABLE AND REPLACEABLE BACKGROUND This invention relates to ahigh voltage vacuum-type circuit breaker and, more particularly, to acircuit breaker of this type which comprises a plurality of vacuuminterrupting units stacked one above the other and electricallyconnected in series. Of interest with respect to this type of circuitbreaker are the following: US. Pat. No. 3,594,525-Miller et al; US. Pat.No. 3,300,609-Flurscheim et al; and U.S. Pat. No. 2,915,6l l-Luehring etal; and British Patents No. 1,080,198-Licentia; and 981,604-Waterton.

Most prior circuit breakers of this type have relied upon a tubularenclosure for supporting and housing the vacuum interrupting units.Typically, this enclosure is of porcelain. A tubular enclosure isusually quite expensive, especially if it is ofporcelain, and has theadditional disadvantage of preventing ready access to the interruptersand their immediately-associated linkages for inspection and adjustment.Moreover, it has not been possible in most prior circuit breakers ofthis general type to replace the individual interrupting units, ifnecessary, without disturbing the remaining interrupting units. Stillanother disadvantage of some prior designs is that they have requiredtensioning members running longitudinally of the enclosure to effectprecompression of the enclosure to enable it to withstand operatingloads and also loads which might be encountered in shipping.

SUMMARY An object of the present invention is to provide a vacuum-typecircuit breaker of the stacked interrupter type which is so constructedthat individual interrupters and their immediately associated linkagesare readily accessible for inspection and adjustment and can be easilyreplaced, if necessary, without disturbing the remaining interruptersand their associated linkages and supporting structure.

Another object is to provide supporting structure which is light inweight, has great strength in the direction that ope rating forces areapplied, is highly resistant to damage from loads encountered duringshipping, and does not require tension members for precompression.

In carrying out the invention in one form, we provide an insulatingsupport and a pair of elongated channels of electrical insulatingmaterial mounted atop the insulating support and extending generallyvertical. Each channel comprises a web and flanges at opposite ends ofthe web. The webs of the two channels are disposed in spaced-apartrelationship, and the flanges project therefrom outwardly away from thespace between the webs. A plurality of interrupter-supporting platesextend generally horizontally across the space between the webs, andfastening means detachably secures the plates to the webs at locationsspaced apart along the length of the webs. A plurality of vacuum-typecircuit interrupters are provided, and they are respectively mounted onthe interrupter-supporting plates, with the housing of each interruptersecured to its associated plate in the space between said webs. Foroperating the interrupters, a longitudinally-movable operating rodextending generally parallel to the longitudinal axis of the channels isprovided in a location laterally spaced from the interrupter-supportingplates. A linkage associated with each interrupter couples the movablecontact rod thereof to the longitudinally-movable operating rod. Each ofthe plates when detached from the webs is removable laterally of thechannels from the space between the webs to permit the plate togetherwith the associated interrupter to be removed from the circuit breaker.

BRIEF DESCRIPTION OF DRAWINGS For a better understanding of theinvention, reference may be had to the following description taken inconjunction with the accompanying drawings, wherein:

FIG. I is a side elevational view of a circuit breaker embodying oneform of the invention.

FIG. 2 is an end view of the circuit breaker shown in FIG. 1.

FIG. 3 is an enlarged sectional view of a portion of the circuit breakerof FIG. 2.

FIG. 4 is a sectional view along the line 44 of FIG.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 1,there is shown a vacuumtype circuit breaker comprising a supportingmetal framework 12 and a vertically-extending porcelain insulating post14 mounted upon the metal framework. Secured in a conventional manner tothe top of the insulating post 14 is a metal end cap 16 that includes apair of spaced-apart vertically-extending lugs 18.

Atop the end cap 16, I mount plurality of vacuumtype circuitinterrupters 20 stacked one above the other and electrically connectedin series. For supporting these interrupters on the end cap 16, Iprovide supporting structure comprising a plurality ofverticallyextending channels 22, each of a high strength electricalinsulating material such as glass-fiber-reinforced polyester resin.

Referring to FIG. 4, each channel is of a U-shaped cross section andcomprises a web 25 and a pair of flanges 26 at opposite edges of theweb. The longitudinal axis 27 of each channel extends generallyvertically. The channels are mounted in spaced-apart relationship withthe flanges 26 of each channel projecting from their web outwardly awayfrom the space between the channels. At the bottom of the supportingstructure, each of the channels 22 bears against one of the lugs 18 onthe end cap 16 and is clamped thereto by bolts 21 extending through theweb and the lugs, as is shown in FIG. 2.

At vertically-spaced locations along the length of the channels, Iprovide interrupter-supporting plates 30, preferably of metal, which aredetachably clamped to the channels. Each of the supporting plates 30comprises a flat body 31 extending between the webs and fasteningprojections, or flanges, 32 at the edges of the flat body which arebolted to the webs. Each of the bolts 34 which clamps a supporting plate30 to a web 25 extends through the web and the projection 32 and isremovable for reasons which will soon appear.

Mounted atop each supporting plate 30 is a vacuumtype circuitinterrupter of a conventional design. As such, each interrupter (FIG. 3)comprises a highly evacuated tubular envelope 40 and a pair of separablecontacts 42 and 43 located within the envelope. The envelope 40comprises a tubular casing 46 of a suitable insulating material such asglass and metal end caps 44 and 45 at opposite ends of the casing joinedto the easing by suitable glass-to-metal seals. Contact 42 is astationary contact supported on a conductive rod 47 which extends insealed relationship through upper end cap 44; and the other contact is amovable contact supported on a reciprocally-movable contact rod 48extending freely through the lower end cap 45. A flexible metallicbellows 50 joined in sealed relationship at its opposite ends to rod 48and end cap 45 provides a seal about rod 48 and permits it to bereciprocated without impairing the vacuum inside envelope 40. It will benoted that contact rod 48 is longitudinally movable in a directionparallel to the longitudinally movable in a direction parallel to thelongitudinal axis 27 of the channels 22.

Referring to FIG. 3, for securing each vacuum interrupter to itssupporting plate 30, each vacuum interrupter is provided with mountingstuds 54 affixed to its lower end cap 45. These studs extend throughopenings in the supporting plate 30 and are provided with nuts 55 whichare tightened to clamp the lower end cap 45 to the supporting plate 30.It is to be noted that supporting plate 30 has a central opening throughwhich movable contact rod 48 freely extends.

For electrically connecting the interrupters in series, I provide aplurality of flexible conductive braids 58. These braids connect themovable contact rod 48 of each interrupter to the stationary contact rod47 of the interrupter immediately therebelow. In the case of the bottominterrupter, another flexible braid 59 connects movable contact rod 48of this interrupter to a lower terminal 60 of the circuit breaker.

For operating the vacuum interrupters substantially simultaneously, Iprovide an elongated operating rod 64 (FIG. 1) of electrical insulatingmaterial that extends generally parallel to the longitudinal axis 27 ofchannels 22 in a position laterally-spaced from interrupter-supportingplates 30. This operating rod 64 is mechanically connected to each ofthe interrupters by linkages 65 respectively associated with theindividual interrupters.

Each linkage 65 comprises a pivotally-mounted operating lever 68pivotally connected at one end to the operating rod 64 and at itsopposite end to movable contact rod 48 of the associated interrupter.Intermediate its ends, operating lever 68 is pivotally supported on apivot 69 carried by spaced-apart arms 70 fixed to supporting plate 30and projecting downwardly therefrom. The pivotal connection to theoperating rod comprises a suitable pivot pin 73 which can be removed bya maintenance man to uncouple the operating lever 68 from rod 64, aswill soon be explained.

The pivotal connection of operating lever 68 to contact rod 48 comprisesa conventional contact-wipe mechanism 75, which includes a downwardlyprojecting rod 76, and a pivot pin 77 connecting lever 68 to rod 76. Thewipe mechanism 75 serves in a conventional manner to maintain pressureon the contacts of the interrupter when they are engaged and to permitsome overtravel at the end of a closing operation to assure that all thecontacts are properly engaged. Reference may be had to FIG. of U.S. Pat.No. 3,025,375- Frank for a more detailed showing of such a wipemechanism.

When operating rod 64 is driven in a downward direction from its openposition of FIG. 1, it acts to simultaneously pivot all the operatinglever 68 in a counterclockwise direction as viewed in FIG. 1. Thisdrives all the movable contact rods 48 upwardly to effect substantiallysimultaneous closing of all of the interrupters. After such closing,opening of the interrupters is effected by allowing operating rod 64 tobe driven in an upward direction from its closed position. This pivotslever 68 in a clockwise direction, enabling the contact rods 48 to bedriven downwardly through a downward opening stroke.

For transmitting operating force to operating rod 64, I provide a loweroperating rod 80 that is pivotally connected at its upper end to anextension of the lowermost operating lower 68. At its lower end, loweroperating rod 80 is pivotally connected to one arm of a bell crank 82.Bell crank 82 is pivotally mounted on a stationary pivot 83. When bellcrank 82 is pivoted counterclockwise about pivot 83, it drives loweroperating rod 80 downwardly to effect counterclockwise motion of thelowermost operating lever 68 and resultant downward motion of operatinglever 64. The lower operating rod 80 is of a suitable insulatingmaterial and is located in laterally spaced relationship with respect toinsulating post 14.

The supporting channels 22 are able to easily withstand any mechanicalforces applied thereto as a result of circuit-breaker operation. Theseforces will typically load the channels in tension. The channels areespecially strong in tension and are able to withstand such tensileforces with little deflection.

The channels 22 are light in weight and low in mass compared to acomparable porcelain supporting structure. This is advantageous inreducing the likelihood of damage from impact forces which might developduring shipping of the circuit breaker. In addition, the channels ofglass-fiber-reinforced resin have a much greater strength than porcelainin tension and in bending, and for this reason alone are more able towithstand without damage forces that might be applied thereto as aresult of shocks encountered during shipping. Because of this highstrength in tension and bending, the channels do not require theprecompression rods that are typically needed by porcelain structures toimpart strength with respect to tensile and bending loads.

It should be appreciated from the above that it is a simple matter for amaintenance man to inspect and adjust the interrupters and theirassociated linkages. Since the space between the channels 22 is open,the maintenance man can easily examine the interrupters when he looksbetween the channels 22 in the direction of arrow 89 in FIG. 1. He canalso make any minor adjustments of the wipe mechanism that might beneeded by reaching into the space between the channels and appropriatelyadjusting the wipe mechanism 75.

If, for some reason, he should desire to remove an interrupter 20 or itsassociated linkage for more extensive adjustments, for repairs or forreplacement, he can readily effect such removal in the following manner.First he removes the associated pivot pin 73 to disconnect the linkage65 in question from operating rod 64. Then he disconnects the braids 58at opposite ends of the interrupter, after which he removes the bolts 34which attach the interrupter-supporting plate 30 to the channels.Thereafter he can slide plate 30 laterally to the right, carrying withit the associated interrupter and the associated linkage, but leavingbehind the channels 22 and the operating rod 64.

He may then make any repairs or replacements which might be desired onthe removed subassembly at a convenient working location, after which hecan return the subassembly to its original position and restore theabove connections.

It will be apparent from the above that removal of any supporting platetogether with the immediately associated interrupter 20 and linkage canbe effected without disturbing any of the other interrupters or theirlinkages or their supporting structure.

In order to improve the voltage distribution between the breaks of thecircuit breaker when they are open, it is often desirable to connectcapacitors in parallel with the breaks. My circuit breaker readily lendsitself to the inclusion of such capacitors, which are shown at 90 inFIG. 4. More specifically, I mount such capacitors 90 on the outer sideof the channels in the space between the flanges of the channel. Eachcapacitor comprises a stack of ceramic disks of the general type shownand claimed in 1.1.8. Pat. No. 3,586,934-Nakata, assigned to theassignee of the present invention. Since these capacitor stacks arenested within the space between the flanges 26, they are advantageouslyprotected by the channels from damage through forces or blowsinadvertently applied in this region.

While I have shown and described a particular embodiment of myinvention, it will be obvious to those skilled in the art that variouschanges and modifications can be made without departing from theinvention in its broader aspects; and I therefore intend herein to coverall such changes and modifications as fall within the true spirit andscope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A vacuum-type circuit breaker comprising a. an insulating support,

b. a pair of elongated channels of electrical insulating material, eachcomprising a web and flanges at opposite ends of said web,

c. means for mounting said channels atop said support with thelongitudinal axis of each channel extending generally vertically, withthe webs of said channels disposed in laterally spaced-apart relation,and with the flanges of each channel projecting from their associatedweb outwardly away from the space between said webs,

d. a plurality of interrupter-supporting plates extending generallyhorizontally across the space between said webs,

e. fastening means for detachably securing said plates to said webs atlocations spaced-apart along the length of said webs,

f. a plurality of vacuum-type circuit interrupters, each comprising anevacuated housing comprising a tubular insulating casing and end caps atopposite ends of said casing, a pair of separable contacts within saidhousing, and a conductive rod supporting a movable one of said contactsand projecting through one end cap of said housing,

g. means for respectively mounting said vacuum interrupters on saidplates in the space between said webs, with said one end cap of eachvacuum interrupter housing secured to an associated one of said plates,the tubular casing of each housing having a longitudinal axis extendinggenerally parallel to the longitudinal axes of said channels,

g. means for electrically connecting said vacuum interrupters in series,

h. a longitudinally-movable operating rod extending generally parallelto the longitudinal axes of said channels in a location laterally spacedfrom said interrupter-supporting plates,

'. and a linkage associated with each interrupter and pivotallysupported on said associated interrupters supporting plate for couplingthe movable contact rod thereof to said longitudinally movable operatingrod,

j. some of said plates, when detached from said webs, being movablelaterally of said channels from the space between said webs to permitsaid detached plates together with the associated interrupter andlinkage to be removed as a unit from said circuit breaker.

2. The vacuum-type circuit breaker of claim 1 in which:

a. the linkage associated with each interrupter comprises an operatinglever, a pivot on which said operating lever is pivotally mountedintermediate the length of said lever, means for supporting said pivoton the associated interrupter-supporting plate, and means for pivotallyconnecting the respective ends of said lever to said operating rod andthe contact rod of the associated interrupter, and

b. said lever is disconnectable from said operating rod to allow saidlinkage to be removed from said circuit breaker with said associatedinterruptersupporting plate but independently of said operating rod.

3. The vacuum-type circuit breaker of claim 1 in which:

a. each of said supporting plates has lateral projections at itsopposite edges that are respectively positioned adjacent said webs,

b. each of said lateral projections is clamped to the web thereadjacentby said fastening means,

c. and each of said fastening means comprises a part extending throughthe associated web in the region of a lateral projection.

4. A vacuum-type circuit breaker as defined in claim 1 and furthercomprising:

a. ceramic capacitors for distributing voltage between saidinterrupters,

b. and means for mounting said ceramic capacitors on one of saidchannels adjacent the outer side of said web in the region between saidflanges.

1. A vacuum-type circuit breaker comprising a. an insulating support, b.a pair of elongated channels of electrical insulating material, eachcomprising a web and flanges at opposite ends of said web, c. means formounting said channels atop said support with the longitudinal axis ofeach channel extending generally vertically, with the webs of saidchannels disposed in laterally spaced-apart relation, and with theflanges of each channel projecting from their associated web outwardlyaway from the space between said webs, d. a plurality ofinterrupter-supporting plates extending generally horizontally acrossthe space between said webs, e. fastening means for detachably securingsaid plates to said webs at locations spaced-apart along the length ofsaid webs, f. a plurality of vacuum-type circuit interrupters, eachcomprising an evacuated housing comprising a tubular insulating casingand end caps at opposite ends of said casing, a pair of separablecontacts within said housing, and a conductive rod supporting a movableone of said contacts and projecting through one end cap of said housing,g. means for respectively mounting said vacuum interrupters on saidplates in the space between said webs, with said one end cap of eachvacuum interrupter housing secured to an associated one of said plates,the tubular casing of each housing having a longitudinal axis extendinggenerally parallel to the longitudinal axes of said channels, g''. meansfor electrically connecting said vacuum interrupters in series, h. alongitudinally-movable operating rod extending generally parallel to thelongitudinal axes of said channels in a location laterally spaced fromsaid interrupter-supporting plates, i. and a linkage associated witheach interrupter and pivotally supported on said associatedinterrupter''s supporting plate for coupling the movable contact rodthereof to said longitudinally movable operating rod, j. some of saidplates, when detached from said webs, being movable laterally of saidchannels from the space between said webs to permit said detached platestogether with the associated interrupter and linkage to be removed as aunit from said circuit breaker.
 2. The vacuum-type circuit breaker ofclaim 1 in which: a. the linkage associated with each interruptercomprises an operating lever, a pivot on which said operating lever ispivotally mounted intermediate the length of said lever, means forsupporting said pivot on the associated interrupter-supporting plate,and means for pivotally connecting the respective ends of said lever tosaid operating rod and the contact rod of the associated interrupter,and b. said lever is disconnectable from said operating rod to allowsaid linkage to be removed from said circuit breaker with saidassociated interrupter-supporting plate but independently of saidoperating rod.
 3. The vacuum-type circuit breaker of claim 1 in which:a. each of said supporting plates has lateral projections at itsopposite edges that are respectively positioned adjacent said webs, b.each of said lateral projections is clamped to the web thereadjacent bysaid fastening means, c. and each of said fastening means comprises apart extending through the associated web in the region of a lateralprojection.
 4. A vacuum-type circuit breaker as defined in claim 1 andfurther comprising: a. ceramic capacitors for distributing voltagebetween said interrupters, b. and Means for mounting said ceramiccapacitors on one of said channels adjacent the outer side of said webin the region between said flanges.